Means for charging storage-battery cells.



O. W. BELL.

MEANS FOR CHARGING STORAGE BATTERY CELLS.

APPLICATION FILED AUG. 19, 1910.

1,023,498. Patented Apr. 16, 1912.

lnmwbov Chas, W Be.

UNITED STATES PATENT OFFICE.

CHARLES W. BELL, OF PHILADELPHIA, IENNSYLVANIA, ASSIGNOR TO THE ELECTRICSTORAGE BATTERY COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORA TIONOF NEW JERSEY.

MEANS FOR CHARGING STORAGE-BATTERY CELLS.

Specification of Letters Patent.

Patented Apr. 16, 1912.

Application filed August 19, 1810. Serial No. 578,025.

To all whom it may concern: I

Be it known that I, CHARLES W. BELL, a subject of His Majesty the Kingof Great Britain, residing in the city of Philadelphia, State ofPennsylvania, have invented certain new and useful Improvements in Meansfor Charging Storage-Battery Cells, of which the following is aspecification.

My invention relates to systems in which a series of storage batterycells is operated in parallel with a generating source, and in which thecurrent in the series is alternately in the charge and dischargedirection. It frequently occurs that in such a system some of the cellsbecome discharged to a lower point than the others, and it is desired torestore these low cells to an equality with the others by permittingthem to receive current when in the charge direction but diverting thecurrent from them when said current is in the discharge direction. Thismay be accomplished by manually operated switches provided thealternations of charge and discharge occur at infrequent and predeter'mined intervals. Where, however, these alterations are of frequentoccurrence, and particularly where it is impossible to determine justwhen they are liable to occur, as, for example, when the storage batteryis being utilized to regulate the fluctuations of a rapidly varyingload, it becomes difficult or impossible to accomplish the results abovedescribed by manual operation.

The object of my invention is to provide automatic means for producii gthese results, that is, for permitting the c. rrent to pass through thelow cells when tha t cprrcnt is in the direction to charge them, buttbdivert the current from these cells when the current is in thedischarge direction.

The nature of my invention will be more clearly understood by referenceto the accompanying drawing, in which G represents a source of directcurrent connected by conductors 1 and 2 to the series of storage batterycells C, C and C The cell C may be taken to represent a low cell, whichit is desired to restore to the same state of charge as the others ofthe series. While this is shown as a single cell, it will be understoodthat it may represent a group of cells con nected in series.

At X is shown an opening in the circuit is connected, by conductors 3and an clcc trolytic valve B which may consist of a plate of aluminium Aand of iron I immersed in any suitable electrolyte such as ammoniumborate. Such a cell will permit current to flow in the direction fromthe iro1. plate to the aluminium plate, but will not permit current toflow in the opposite direction. Thus, when the direction of currentthrough the entire series of storage battery cells is in the chargingdirection. this electrolytic valve, if properly connected into thecircuit, will permit said current to flow through the cell C In a shuntcircuit around the cell C consisting of conductors 3 and 4. there isshown a second electrolytic valve B which may be constructed in the samemanner as described in connection with B, except that the polarity isreversed, the aluminium plate A being connected to conductor 3 and theiron plate I being connected to conductor 4. When the current in theseries of storage battery cells is in the discharge direction,thissecond electrolytic valve will permit such current to flow aroundthe cell C, while the electrolytic valve B will prevent any of saidcurrent from passing through the cell G On the other hand when thecurrent in the series of storage battery cells is in the chargedirection, the electrolytic valve B will prevent any portion of saidcurrent. from-flowing through the shunt circuit 3ft compelling saidcurrent to pass through the cell C Thus, the cell C will automaticallybe. subjected to the charging current, but will be relieved from thedischarge current, and will thereby in time be brought up to the samestate of charge as the rest of the series.

It will he understood that. modifications may be made in the details ofthe invention without altering the spirit thereof, and

\Vhat I claim and desire to secure by Letters Patent is;

1. The combination with a series of sin!- age cells of apparatus forchanging the relative state of charge of a selected portionot' theseries comprising a device interposed in series with the selectedportion. and adapted to permit a How of current in one direction andprevent a How in the opposite direction, and another device in shuntwith the selected portion and the first named device and adapted topermit the passage of curbetween cells C and C into which opening rentin the direction opposed by the first (ill named device but oppose aflow of current in the opposite direction.

2. The combination with a series of storage cells of apparatus forchanging the relative state of charge of a selected or tion of theseries comprising an electro ytic valve interposed in series with theselected portion and adapted to permit a flow of current in onedirection and prevent a flow in the opposite direction, and anotherelectrolytic valve in shunt with the selected portion and the firstnamed electrolytic valve and adapted to permit the passage of current inthe directlon opposed by the first named electrolytic valve but oppose aflow of current in the opposite direction.

3. In combination, two branch circuits in parallel relation, eachcontaining an electrolytic valve, said valves being oppositelyconnected, and a series of storage cells whereof a portion is connectedin one of said branch circuits while the remainder is connected inseries with both branch circuits, whereby current in one directionpasses through the entire series of storage cells, while current in theother direction is shunted around the portion in the branch circuit.

4. In combination, two branch circuits connected in parallel relation,automatic means for changing the proportionate division of currentbetween them with change of direction of current flow, and a series ofstorage cells whereof a ortion is connected in one of said branchcircuits While the remainder is connected in series with both branchcircuits whereby a greater proportion of the total current passesthrough the portion in the branch circuit in one direction than in theother.

In testimony whereof, I have hereunto signed my name.

CHAS. W. BELL. Witnesses:

J. H. TRACY, A. H. Nam.

